Snow and Ice Overview
A tenth of Earth's land surface is permanently occupied by ice sheets or glaciers, but the domain of the cryosphere – that part of the world where snow and ice can form – extends three times further still.
The cryosphere is an important regulator of global climate, its bright albedo reflecting sunlight back to space and its presence influencing regional weather and global ocean currents. Some 77% of the globes freshwater are bound up within the ice – but the cryosphere appears disproportionately sensitive to the effects of global warming.
Imaging radar systems like those of ERS and Envisat pierce through clouds or seasonal darkness to chart ice extent, possessing sensitivity to different ice types – from kilometers-thick ice sheets to new-born floating ‘pancake' ice – supplemented by optical observations.
Radar altimeters gather data on changing ice height and mass: ESA's CryoSat is the first altimetry mission specifically designed to accurately measure the thickness of sea ice and land ice margins.
Snow and Ice News
13 December 2019
It is now almost 10 years since ESA's CryoSat was launched. Throughout its decade in orbit, this novel satellite, which carries a radar altimeter to measure changes in the height of the world's ice, has returned a wealth of information about how ice sheets, sea ice and glaciers are responding to climate change. One of the most recent findings from this extraordinary mission shows how it can be used to map changes in the seaward edges of Antarctic ice shelves.
10 December 2019
The Greenland ice sheet is losing mass seven times faster than in the 1990s, according to new research.
Specific Topics on Snow and Ice
The enormous permafrost areas of the world show seasonal change which has impact on not only vegetation and hydrological cycles, but also on the planning and safety of huge gas and oil pipelines which traverse these areas.
Sea ice is formed from ocean water that freezes, whether along coasts or to the sea floor (fast ice) or floating on the surface (drift ice) or packed together (pack ice). The most important areas of pack ice are the polar ice packs. Because of vast amounts of water added to or removed from the oceans and atmosphere, the behavior of polar ice packs have a significant impact of the global changes in climate.
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